DOI

Hong Liang, Key Laboratory of National Population and Family Planning Commission (NPFPC), Shanghai Institute of Planned Parenthood Research (SIPPR), Institute of Reproductive Development (IRD), Fudan University, Jianping Chen, Key Laboratory of National Population and Family Planning Commission (NPFPC), Shanghai Institute of Planned Parenthood Research (SIPPR), Institute of Reproductive Development (IRD), Fudan University, Maohua Miao, Key Laboratory of National Population and Family Planning Commission (NPFPC), Shanghai Institute of Planned Parenthood Research (SIPPR), Institute of Reproductive Development (IRD), Fudan University, Wei Yuan, Key Laboratory of National Population and Family Planning Commission (NPFPC), Shanghai Institute of Planned Parenthood Research (SIPPR), Institute of Reproductive Development (IRD), Fudan University,